Study Finds Big Geographic Swings In Psychotropic Drug Use

In Alexandria, Va., the rate of antidepressant use is the highest in the country, with a full 40 percent of residents receiving prescriptions.

Cape Cod, Mass., tops the country in the use of stimulants, with 16 percent of the population filling at least one prescription, compared to a mean of 2.6 percent nationally.

Gainsville, Fla., has the highest utilization rate of antipsychotics – 4.6 percent of residents, well above the national mean of .8 percent.

Usage rates of the three classes of mental health medications vary widely across the U.S., with Connecticut in the middle, according to a new study by the Yale School of Management. The study found that much of the geographic variation could be explained by access to health care and pharmaceutical marketing efforts, rather than by the underlying prevalence rate of the psychiatric disorders.

For all three classes of medications, use rates were higher in areas with better access to health care, as measured by the number of physicians in a three-digit zip code area. More surprisingly, the study found that in regions of the country where pharmaceutical companies spent the most money marketing drugs, the utilization rate of psychotropic medications was at least 10 percent higher than in areas with the lowest marketing expenditures.

The study is the first to demonstrate that "marketing efforts have a substantial impact on utilization rates," said Marissa King, assistant professor of organizational behavior at the Yale School of Management and the study's lead author. "There's a huge geographic variability in utilization rates, and it appears that part of the puzzle is marketing."

King and co-author Connor Essick of the Yale School of Public Health examined 2008 national data on retail prescriptions for antipsychotics, stimulants and antidepressants. They mapped patterns in usage rates, both across the country and within states. Clusters of high use were identified, including one in the south, centered on Tennessee.

Within Connecticut, the New Haven area had the highest rate of antidepressant use – 14.7 percent, compared to the mean of 10.4 percent nationally. Stimulant use was highest in Stamford – 3.9 percent, compared to 2.6 percent nationally. Antipsychotic use was highest in the Hartford area – 3.8 percent, compared to the .8 percent national mean.

The Bridgeport area recorded the lowest rates of stimulant and antidepressant prescribing (1.6 percent and 7.4 percent, respectively), while antipsychotic use was lowest in the Stamford zip code area (1.3 percent).

Nationally, the study found that use of the psychotropic medications was lowest in the western part of the U.S., with clusters of high use in other regions. In a large area of the South centered on Tennessee, for example, use of antidepressants, antipsychotics and stimulants was 40 percent higher than in the rest of the country. Residents in this region were 77 percent more likely than people outside the cluster to be using stimulants, the study found.

The cluster in the South overlaps with an area known as the "stroke belt," an 11-state region that has been recognized by public health authorities as having an unusually high incidence of stroke, cardiovascular disease and lung cancer. The finding of a high use of psychotropic drugs in that region raises questions about possible links between mental health treatment and other health outcomes, King said.

King said she was surprised that the geographic differences in usage were not explained by the underlying prevalence of depression or related mental health disorders. The exception was stimulant use, which correlated to states' ADHD prevalence rates.

"I was definitely surprised that prevalence wasn't a determining factor," she said.

Instead, the study points to other reasons for the variability – namely, pharmaceutical marketing efforts and access to health care. Pharmaceutical companies pay doctors to promote their drugs and are likely to direct marketing dollars to areas that have large numbers of physicians, the study says. Antidepressants, antipsychotics and stimulants are among the most heavily marketed – and highest-grossing – medications.

"By shaping patients' and physicians' knowledge about existing treatment options, as well as perceptions about the appropriateness of given treatments, marketing efforts may be an important factor in health care utilization," King and Essick wrote.

Because of recent public disclosures by drug companies of their payments to doctors for speaking and consulting services, King and Essick were able to track correlations between marketing expenditures and prescribing rates. The correlations were not exact: expenditures were from 2008 and 2009, while prescriptions were from 2008 only. Federal "sunshine act" provisions require pharmaceutical companies to report all payments to physician speakers and consultants beginning this year; some drug companies have already started providing that data.

King said she expects the public disclosures of physician payments to prompt more studies of prescribing and usage patterns.

"I think with the sunshine act, having the information available to researchers on a much larger scale will help us look at how marketing is influencing prescribing behavior," she said.

This story was reported under a partnership with the Connecticut Health I-Team (www.c-hit.org)